Thermoplastic molding process and apparatus

ABSTRACT

A system and method for forming an article from thermoplastic material and fiber. The method includes heating thermoplastic material to form a molten thermoplastic material for blending with the fiber. The molten thermoplastic material is blended with the fibers to form a molten composite material having a concentration of fiber by weight. The molten composite material may then be extruded through dynamic dies to deliver discrete controlled material that is gravitated onto a lower portion of a mold. The lower portion of the mold may be moved in space and time while receiving the flow of composite material to deposit a predetermined quantity of molten composite material thereon conforming to mold cavities of the lower and an upper portion of the mold. The upper portion of the mold may be pressed against the predetermined quantity of molten composite material and closing on the lower portion of the mold to form the article.

CROSS-REFERENCES TO RELATED APPLICATIONS

This Application for Patent claims the benefit of priority from, andhereby incorporates by reference the entire disclosure of, co-pendingU.S. application for patent Ser. No. 08/993,516, filed Dec. 18, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thermoplastic molding process andapparatus and especially to a thermoplastic process and apparatus usinga proprietary dynamic gated die having adjustable gates for varying thethickness of the extruded material, which material is molded as it ispassed from the extrusion die.

2. Description of the Related Art

In the past it has been common to provide a wide variety of moldingsystems including the molding of a thermoplastic resin or athermoplastic composite part. In vacuum molding, a slab (constantthickness sheet) of heated thermoplastic material is placed on thevacuum mold and a vacuum drawn between the mold and the heated plasticmaterial to draw the plastic material onto the mold. Similarly, incompression molding, a lump or slab of preheated material is pressedbetween two molding forms which compress the material into a desiredpart or shape.

Related Patents

Prior U.S. patents which use thermoforming of material can be seen inthe four Winstead patents, U.S. Pat. Nos. 4,420,300; 4,421,712;4,413,964; and 3,789,095. The Winstead '712 and '300 patents are for anapparatus for continuous thermoforming of sheet material including anextruder along with stretching means and a wheel having a female modethereon and a plurality of plug-assist means interlinked so as to forman orbiting device having a plug-assist member engaging the sheetmaterial about a substantial arc of wheel surface. The Winstead '964patent teaches an apparatus for continuously extruding and formingmolded products from a web of thermoplastic material while continuouslyseparating the product from the web, stacking and handling the products,and recycling the web selvage for further extrusion. The apparatus usesmultiple mode cavities in a rotating polygon configuration over aperipheral surface of which the biaxially oriented web is continuouslypositioned by a follower roller interfacing the polygon with a biaxialorientation device. The Winstead patent U.S. Pat. No. 3,789,095 is anintegrated method of continuously extruding low density formthermoplastic material and manufacturing three-dimensional formedarticles therefrom.

The Howell U.S. patent, U.S. Pat. No. 3,868,209, is a twin sheetthermoformer for fabricating a hollow plastic object from a pair ofheat-fusible thermoplastic sheets which are serially moved in a commonhorizontal plane from a heating station to a mold mechanism at a formingstation. The Held, Jr. patent, U.S. Pat. No. 3,695,799, is an apparatusfor vacuum forming hollow articles from two sheets of thermoplasticmaterial by passing the sheets of material through a heating zone whilein a spaced relationship and between two mold halves. The mold halvesare brought together as a vacuum is pulled on each sheet to cause it toconform to the shape of its respective mold so as to mold a hollowarticle. The Budzynski et al., U.S. Pat. No. 5,551,860, is a blowmolding apparatus for making bottles which have rotating moldscontinuously rotating while aligning one mold at a time with anextrusion die handle for loading the mold. The Hujik patent, U.S. Pat.No. 3,915,608, is an injection molding machine for multi-layered shoresoles which includes a turntable for rotating a plurality of moldsthrough a plurality of work stations for continuously molding shoesoles. The Ludwig patent, U.S. Pat. No. 3,302,243, is another apparatusfor injection molding of plastic shoes. The Lameris et al. patent, U.S.Pat. No. 3,224,043, teaches an injection molding machine having at leasttwo molds which can be rotated for alignment with plastic injectingnozzles. The Vismara patent, U.S. Pat. No. 4,698,001, is a machine formanufacturing molded plastic motorcycle helmets and which uses acompression type mold in which a pair of mold halves is shifted betweenpositions. The Krumm patent, U.S. Pat. No. 4,304,622, is an apparatusfor producing thick slabs of thermoplastic synthetic resins whichincludes a pair of extruders, each extruding a half slab strand to arespective roller assembly. The roller assemblies have final rollerswhich form a consolidation nip between them in which the two half slabsare bonded together.

Composites and Other Processes

Composites are materials formed from a mixture of two or more componentsthat produce a material with properties or characteristics that aresuperior to those of the individual materials. Most composites comprisetwo parts, namely a matrix component and reinforcement component(s).Matrix components are the materials that bind the composite together andthey are usually less stiff than the reinforcement components. Thesematerials are shaped under pressure at elevated temperatures. The matrixencapsulates the reinforcements in place and distributes the load amongthe reinforcements. Since reinforcements are usually stiffer than thematrix material, they are the primary load-carrying component within thecomposite. Reinforcements may come in many different forms ranging fromfibers, to fabrics, to particles or rods imbedded into the matrix thatform the composite.

Composite structures have existed for millions of years in nature.Examination of the microstructure of wood or the bioceramics of aseashell reveals the occurrence of composites found in nature andindicates that modern composite materials have essentially evolved tomimic structures found in nature. A perfect example of a compositematerial is concrete. Different forms of concrete offer an insight as tohow reinforcements work. The cement acts as the matrix, which holds theelements together, while the sand, gravel, and steel, act asreinforcements. Concrete made with only sand and cement is not nearly asstrong as concrete made from cement, sand, and stones, which, in turn,is not as strong as concrete reinforced with steel, sand and stones. Thematrix and reinforcement materials of concrete are blended, poured andmolded, typically in a form structure. In the generation of parts madewith other composite materials, the shape of a composite structure orpart is determined by the shape or geometry of the mold, die or othertooling used to form the composite structures.

There are many different types of composites, including plasticcomposites. Each plastic resin has its own unique properties, which whencombined with different reinforcements create composites with differentmechanical and physical properties. If one considered the number ofplastic polymers in existence today and multiplied that figure by thenumber of reinforcements available, the number of potential compositematerials is staggering. Plastic composites are classified within twoprimary categories: thermoset and thermoplastic composites.

In the case of thermoset composites, after application of heat andpressure, thermoset resins undergo a chemical change, which cross-linksthe molecular structure of the material. Once cured, a thermoset partcannot be remolded. Thermoset plastics resist higher temperatures andprovide greater dimensional stability than most thermoplastics becauseof the tightly cross-linked structure found in thermoset plastic.Thermoplastic matrix components are not as constrained as thermosetmaterials and can be recycled and reshaped to create a new part. Commonmatrix components for thermoplastic composites include polypropylene(PP), polyethylene (PE), polyetheretherketone (PEEK) and nylon.Thermoplastics that are reinforced with high-strength, high-modulusfibers to form thermoplastic composites provide dramatic increases instrength and stiffness, as well as toughness and dimensional stability.

Composite materials are used in numerous applications across a broadrange of industries. Typically, composites are used to replace productsmade of metal alloys or multi-component metal structures assembled withfasteners or other connectors. Composites offer sufficient strength,while providing a reduction in weight. This is particularly important inindustries such as automotive and aerospace, where the use of compositematerials results in lighter, faster, more fuel-efficient andenvironmentally robust aircraft and automobiles. Composites may also bedesigned to replace wood, fiberglass and other more traditionalmaterials. The following is a partial list of industries that may haveapplication for the use of large parts made from thermoplastic compositematerials: aerospace, automotive, construction, home appliance, marine,material handling, medical, military, telecommunications, transportationand waste management.

In general, among other attributes, thermoplastic composite materialsare resistant to corrosion and offer long fatigue lives making themparticularly attractive for many manufacturers. The fatigue life refersto the period of time that a part lasts prior to exhibiting materialwear or significant stress, to the point of impairing the ability of thepart to perform to specification. Typically, composites are utilized inapplications where there is a desire to reduce the weight of aparticular part while providing the strength and other desirableproperties of the existing part. There are a number of parts made fromthermoset composite materials that are quite expensive. These types ofparts are typically referred to as advanced composite materials and areutilized most often in the military and aerospace industries.

Product development engineers and production engineers believe thatthermoplastic composite materials will play an ever-increasing role inmodern technological development. New thermoplastic resins are regularlydeveloped and more innovative methods of manufacturing are beingintroduced to lower the costs associated with manufacturing parts madefrom composite materials. As the cost for manufacturing parts made withthermoplastic composite materials reduces, the use of thermoplasticcomposites becomes a more viable solution for many commercial andindustrial applications.

Molding Methods Currently Available for Thermoplastic Composites

Most of the commercially available manufacturing technology forthermoplastic composites was adapted from methods for processingthermoset composites. Since these methods are designed for resin systemswith much lower viscosities and longer cure times, certaininefficiencies and difficulties have plagued the thermoplasticmanufacturing process. There are several methods of manufacturing withthermoplastic composites currently in use. Some of the most commonprocesses include compression molding, injection molding, and autoclaveprocessing, all of which can be used for the production of “near-netshape” parts, i.e., parts that substantially conform to the desired ordesigned shape after molding. Less common methods for processthermoplastic composites include pultrusion, vacuum forming, diaphragmforming and hot press techniques.

Compression Molding

Compression molding is by far the most widespread method currently usedfor commercially manufacturing structural thermoplastic compositecomponents. Typically, compression molding utilizes a glass matthermoplastic (GMT) composite comprising polypropylene or a similarmatrix that is blended with continuous or chopped, randomly orientedglass fibers. GMT is produced by third-party material compounders, andsold as standard or custom size flat blanks to be molded. Using thispre-impregnated composite (or pre-preg as it is more commonly calledwhen using its thermoset equivalent), pieces of GMT are heated in anoven, and then laid on a molding tool. The two matched halves of themolding tool are closed under great pressure, forcing the resin andfibers to fill the entire mold cavity. Once the part is cooled, it isremoved from the mold with the assistance of an ejecting mechanism.

Generally, the matched molding tools used for GMT forming are machinedfrom high strength steel to endure the continuous application of thehigh molding pressure without degradation. These molds are oftenactively heated and cooled to accelerate cycle times and improve thesurface finish quality. GMT molding is considered one of the mostproductive composite manufacturing processes with cycle times rangingbetween 30 and 90 seconds. Compression molding does require a highcapital investment, however, to purchase high capacity presses(2000-3000 tons of pressure) and high pressure molds, therefore it isonly efficient for large production volumes. Lower volumes of smallerparts can be manufactured using aluminum molds on existing presses tosave some cost. Other disadvantages of the process are low fiberfractions (20% to 30%) due to viscosity problems, and the ability toonly obtain intermediate quality surface finishes.

Injection Molding

Injection molding is the most prevalent method of manufacturing fornon-reinforced thermoplastic parts, and is becoming more commonly usedfor short-fiber reinforced thermoplastic composites. Using this method,thermoplastic pellets are impregnated with short fibers and extrudedinto a closed two-part hardened steel tool at injection pressuresusually ranging from 15,000 to 30,000 psi. Molds are heated to achievehigh flow and then cooled instantly to minimize distortion. Using fluiddynamic analysis, molds can be designed which yield fibers with specificorientations in various locations, but generically injection moldedparts are isotropic. The fibers in the final parts typically are no morethan one-eighth (⅛)″ long, and the maximum fiber volume content is about40%. A slight variation of this method is known as resin transfermolding (RTM). RTM manufacturing utilizes matted fibers that are placedin a mold which is then charged with resin under high pressure. Thismethod has the advantages of being able to manually orient fibers anduse longer fiber lengths.

Injection molding is the fastest of the thermoplastic processes, andthus is generally used for large volume applications such as automotiveand consumer goods. The cycle times range between 20 and 60 seconds.Injection molding also produces highly repeatable near-net shaped parts.The ability to mold around inserts, holes and core material is anotheradvantage. Finally, injection molding and RTM generally offer the bestsurface finish of any process.

The process discussed above suffers from real limitations with respectto the size and weight of parts that can be produced by injectionmolding, because of the size of the required molds and capacity ofinjection molding machines. Therefore, this method has been reserved forsmall to medium size production parts. Most problematic from astructural reinforcing point is the limitation regarding the length ofreinforcement fiber that can be used in the injection molding process.

Autoclave Processing

Autoclave processing is yet another thermoplastic compositemanufacturing process used by the industry. Thermoplastic prepregs withunidirectional fibers or woven fabrics are laid over a single sidedtool. Several layers of bagging material are placed over the prepregassembly for surface finish, to prevent sticking, and to enable a vacuumto be drawn once it is placed in an autoclave. Inside the autoclave, thecomposite material is heated up and put under pressure to consolidateand cross-link the layers of material. Unlike compression and injectionmolding, the tool is an open mold and can be made of either aluminum orsteel since the pressures involved are much lower.

Because the autoclave process is much slower and more labor intensive,it is utilized primarily for very large, low volume parts that require ahigh degree of accuracy; it is not conducive for production lines.Significant advantages of this method include high fiber volumefractions and control of the fiber orientation for enabling specificmaterial properties. This process is particularly useful for prototypingbecause the tooling is relatively inexpensive.

Molding Methods for Thermoplastic Composites Requiring “Long” Fibers

None of the processes described above are capable of producing athermoplastic composite reinforced with long fibers (i.e., greater thanabout one-half inch) that remain largely unbroken during the moldingprocess itself, this is especially true for the production of large andmore complex parts. Historically, a three-step process was utilized tomold such a part: (1) third party compounding of pre-preg compositeformulation; (2) preheating of pre-preg material in oven; and, (3)insertion of molten material in a mold to form a desired part. Thisprocess has several disadvantages that limit the industry's versatilityfor producing more complex, large parts with sufficient structuralreinforcement.

One disadvantage is that the sheet-molding process cannot produce a partof varying thickness, or parts requiring “deep draw” of thermoplasticcomposite material. The thicker the extruded sheet, the more difficultit is to re-melt the sheet uniformly through its thickness to avoidproblems associated with the structural formation of the final part. Forexample, a pallet having feet extruding perpendicularly from the topsurface is a deep draw portion of the pallet that cannot be molded usinga thicker extruded sheet because the formation of the pallet feetrequires a deep draw of material in the “vertical plane” and, as such,will not be uniform over the horizontal plane of the extruded sheet.Other disadvantages associated with the geometric restrictions of anextruded sheet having a uniform thickness are apparent and will bedescribed in more detail below in conjunction with the description ofthe present invention.

The present invention is directed towards a molding system for producinga thermoplastic resin of thermoplastic composite parts using either avacuum or compression mold with parts being fed directly to the moldsfrom an extrusion die while the thermoplastic slab still retains theheat used in heating the resins to a fluid state for forming the sheetsof material through the extrusion die. The present invention relates toa thermoplastic molding process and apparatus and especially to athermoplastic process and apparatus using a thermoplastic extrusion diehaving adjustable gates for varying the thickness of the extrudedmaterial, which material is molded as it is passed from the extrusiondie.

The present invention is further directed towards a continualthermoforming system which is fed slabs of thermoplastic materialdirectly from an extruder forming the slabs of material onto a moldwhich can be rotated between stations. The thermoplastic material isextruded through an extrusion die which is adjustable for providingdeviations from a constant thickness plastic slab to a variablethickness across the surface of the plastic slab. The variable thicknesscan be adjusted for any particular molding run or can be continuouslyvaried as desired. This allows for continuous molding or thermoplasticmaterial having different thickness across the extruded slab and throughthe molded part to control the interim part thickness of the molded partso that the molded part can have thick or thin spots as desiredthroughout the molded part. The present invention is not limited as tosize, shape, composition, weight or strength of a desired partmanufactured by the extrusion molding process.

SUMMARY OF THE INVENTION

A thermoplastic molding system includes a thermoplastic extrusion diefor the extrusion of a thermoplastic slab profiled by adjustable diegate members, i.e., dynamic die settings, for varying the thickness ofthe extruded material in different parts of the extruded slab. Thethermoplastic extrusion die has a trimmer for cutting the extrudedthermoplastic slab from the thermoplastic extrusion die. A plurality ofthermoplastic molds, which may be either vacuum or compression molds,are each mounted on a movable platform, such as a rotating platform, formoving one mold at a time into a position to receive a thermoplasticslab being trimmed from the thermoplastic extrusion die. A molded partis formed with a variable thickness from a heated slab of thermoplasticmaterial being fed still heated from the extrusion die. A plurality ofmolds are mounted to a platform to feed one mold into a loading positionfor receiving a thermoplastic slab from the extrusion die and a secondmold into a release position for removing the formed part from the mold.The platform may be a shuttle or a rotating platform and allows eachmolded part to be cooled while another molded part is receiving athermoplastic slab. A thermoplastic molding process is provided havingthe steps of selecting a thermoplastic extrusion die setting inaccordance with the apparatus adjusting the thermoplastic extrusion diefor varying the thickness of the extruded material passing therethroughin different parts of the extruded slab The thermoplastic material isheated to a fluid state and extruded through the selected thermoplasticdie which has been adjusted for varying the thickness of the extrudedmaterial in different parts of the extruded slab, trimming the extrudedthermoplastic slab having a variable thickness to a predetermined size,and directing each trim slab of heated thermoplastic material onto athermoforming mold, and molding a predetermined part in the mold so thatthe molded part is formed with a variable thickness from a slab ofmaterial heated during extrusion of the material.

“This extrusion-molding” process also facilitates the formation ofthermoplastic composite structures reinforced with long fibers (greaterthan about one-half inch) because the extruder dispenses the molten,thermoplastic composite material through the dynamic die, gravitatingthe material directly onto a lower mold that is movable with respect tothe position of the dynamic die. As used herein, the term “lower mold”refers to the lower half of a matched-mold into which thermoplasticmaterial is directed. Similarly, the term “upper mold” refers to theupper half of the matched-mold within which the desired thermoplasticpart is formed, when the upper and lower mold halves are combined i.e.,closed. The lower mold may be moved via a trolley to fill the cavity ofthe mold with varying quantities of the thermoplastic compositematerial. For example, if the cavity defined by the lower and an uppermold is larger over a certain horizontal range, the lower mold may beslowed down to receive more molten thermoplastic composite material inthat region. The dynamic die employs flow control elements that vary orregulate the flow of the molten extruded thermoplastic compositematerial to deliver different quantities of material from each of theflow control element, to deposit the material selectively across thewidth of the lower mold in a direction perpendicular to the direction itis moving. The thermoplastic composite material may be molded with longfibers (greater than about one-half inch) having a concentration of atleast ten percent (10%) by weight to as much as fifty to sixty percent(50-60%) by weight, with low fiber-fracture rates. After the moltenextruded thermoplastic composite material gravitates onto the lowermold, the trolley is automatically transported into a press that closesthe upper mold onto the lower mold to form the composite part.

One embodiment according to the principles of the present inventionincludes a system and method for forming an article from thermoplasticmaterial and fiber. The method includes heating thermoplastic materialto form a molten thermoplastic material while blending with the fiber.The molten thermoplastic material is blended with the fibers to form amolten composite material having a desired concentration of fiber byweight and/or volume. The molten composite material may then be extrudedthrough the dynamic die to form a prescribed flow of composite materialand gravitated onto a lower portion of a mold for forming the article.The lower mold may be discretely moved in space and time at varyingspeeds while receiving the flow of composite material to deposit apredetermined quantity of molten composite material thereon conformingexactly to the amount of material required in the mold cavity of thelower mold. The upper portion of the mold may be pressed against thepredetermined quantity of molten composite material and closing on thelower portion of the mold to form the article.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, and advantages of the present invention will beapparent from the written description and the drawings in which:

FIG. 1 is a top plan view of a molding system in accordance with thepresent invention;

FIG. 2 is a side elevation view of the molding apparatus of FIG. 1;

FIGS. 3A-3E are plan views of the mold of FIGS. 1 and 2 in differentsteps of the process of the present invention;

FIG. 4 is a side elevation of the extruder of FIGS. 1 and 2;

FIG. 5 is a rear elevation of the extruder of FIG. 4;

FIG. 6A is an exemplary schematic diagram of an extrusion-molding systemaccording to FIG. 1 operable to form structural parts;

FIG. 6B is another exemplary block diagram of the extrusion-moldingsystem 600 a of FIG. 6A;

FIG. 7 is an exemplary exploded view of the dynamic die of FIG. 6Adepositing the extruded composite material on the lower mold assupported by the trolley;

FIG. 8A is an exemplary flow diagram describing the extrusion-moldingprocess that may be utilized to form articles or structural parts byusing either two- or three-axis control for depositing the compositematerial onto the lower mold of FIG. 6A;

FIG. 8B is an another exemplary flow diagram for producing structuralparts utilizing the extrusion-molding system of FIG. 6A via thethree-axis control extrusion-molding process;

FIG. 9 is an exemplary block diagram of a controller of FIG. 6Ainterfacing with controllers operating in components of theextrusion-molding system of FIG. 6A;

FIG. 10 is a more detailed exemplary block diagram of the controller ofFIG. 6A;

FIG. 11 is an exemplary block diagram of the software that is executedby a processor operating the controller of FIG. 10;

FIG. 12 is an exemplary schematic of the flow control elements and alower mold, which is sectioned into a grid, to deposit extrudedcomposite material in accordance with the extrusion-molding system ofFIG. 6A;

FIG. 13 is a top view of the flow control elements as aligned to depositthe composite material onto the lower mold of FIG. 6A;

FIG. 14 is an exemplary perspective top view of a corner of a palletproduced by the extrusion-molding system of FIG. 6A;

FIGS. 15A and 15B are an exemplary perspective bottom and top views,respectively, of a platform having hidden ribs formed by theextrusion-molding system of FIG. 6A,

FIGS. 16A and 16B are an exemplary structural parts having insertsformed by the extrusion-molding system of FIG. 6A; and

FIG. 17 is an exemplary flow diagram describing the operations forembedding an insert, such as a fastener, support, or other element, intoa structural part, such as those shown in FIGS. 16A and 16B, utilizingthe extrusion-molding system of FIG. 6A.

DETAILED DESCRIPTION OF THE INVENTION

For many years, a gap has existed in the composites manufacturingindustry that failed to provide a process to mass produce largethermoplastic composite structures or parts at the rates and laborefficiencies of compression or injection molding, with the accuracy andlow pressures of autoclave molding. The principles of the presentinvention provide for processes that closes this gap and produces suchthermoplastic composite parts. The processes are suitable for mid tohigh production volumes of parts, and may produce large parts andstructures with high reinforcing fiber concentration and at low moldingpressures.

Referring to FIGS. 1 and 2 of the drawings, a thermoforming apparatus 10for thermoforming parts from a thermoplastic resin or from athermoplastic composite is illustrated having an extruder 11, a moldexchange station 12, and a compression mold station 13. The extruder hasa hopper 14 mounted on top for feeding a thermoplastic resin orcomposite material into an auger 15 where heaters are heating thethermoplastic material to a fluid material while the auger is feeding italong the length of the extruder path to an extrusion die 16 at the endthereof. The material being fed through the extruder and out theextrusion die is cut with a trimmer 17 mounted at the end of the die 16.The material is extruded in a generally flat plate slab (not shown) andis trimmed at predetermined points by the trimmer 17 as it leaves theextrusion die 16. A support platform 18 will support a traveling moldhalf 19 directly under the extrusion die 16 for receiving a slab ofthermoplastic material. The traveling mold half 19 has wheels 20 whichallow the mold half 19 to be moved from the platform 18 onto a rotatingplatform 21 (shown as mold half 19′) which is mounted on a centralrotating shaft 22 for rotation as indicated by the bidirectional arrow21′ in FIG. 1. The rotating platform 21 will have a second mold half 23thereon which can be fed into the compression molding station 13 (shownas mold half 23′) while the mold half 19 is on the platform 18. The moldhalf 23′ can be supported on a stationary platform 24 in the compressionstation directly beneath a common posing fixed mold half 25 mounted to amoving platen 26 where the molding operation takes place. Thus, the moldhalves 19 and 23 can shuttle back and forth so that one mold can becapturing a thermoplastic slab while the other mold half is molding apart. Each of the traveling mold halves 19, 23 has an electric motor 27for driving the mold half from the rotating platform 21 onto theplatform 18 or onto the stationary platform 24. A linear transducer 28can be mounted on the platform 18 for controlling the traveling moldhalves speed.

It should be noted at this point that the extruder 11 produces theheated extruded slab still containing the heat energy onto the travelingmold half where it is delivered to the compression mold 13 and moldedinto a part without having to reheat a sheet of thermoplastic material.As will also be noted hereinafter in connection with FIGS. 4 and 5, thethermoplastic slab can also be of variable thickness throughout itswidth to enhance the thermoformed part made from the mold.

Turning to FIGS. 3A-3E, the thermoplastic molding apparatus 10 isillustrated having the mold halves 19, 19′ and 23, 23′ in a series ofpositions in the operation of the press in accordance with the presentinvention. Each figure has the extruder 11 having the hopper 14 feedingthe thermoplastic resin or composite material into an auger 16 where itis heated before being extruded. In FIG. 3A, mold half 23′ is empty andmold half 19 is being charged with a hot melt directly from the extruder11. In FIG. 3B, the mold carrier moves the mold halves 19 and 23′ on therotating turntable 21. In FIG. 3C, the rotating turntable 21 rotates onthe central axis shaft 22 (not shown) between stations for loading aslab onto one mold half 23 and a loaded mold half 19′ into thecompression or vacuum molding machine 13. In FIG. 3D, the mold half 19′travels into the press 13 while the empty mold half 23 travels under theextrusion die 16 for loading with a slab of thermoplastic material. InFIG. 3E, the mold half 19′ is press cooled and the part is ejected whilemold half 23 is charged with a hot melt as it is moved by its carrierbelow the extrusion die 16 until completely charged.

Turning to FIGS. 4 and 5, the extrusion die 30 is illustrated having thedie body 31 having the channel 32 for the feeding of a fluidthermoplastic material with the auger 15 of FIGS. 1 and 2 therethroughout the extrusion channel 33 to produce a sheet or slab of thermoplasticextruded material from the mouth 34. The die 30 has a plurality of gatedplates 35 each connected to a threaded shaft 36 driven by a gateactuator motor 37 which can be a hydraulic or pneumatic motor but, asillustrated, is an electrical stepper motor having a control line 38feeding to a remote controller 40 which can step the motor 37 in stepsto move the plate 35 in and out to vary the thickness of thethermoplastic slab passing the channel portion 41. A plurality of anynumber of motors 37 can be seen in FIG. 5 driving a plurality of plates,each mounted abutting the next plate, and each plate controlledseparately to thereby vary the plates 35 in the channel 41 in a widevariety of patters for producing a slab out the output portion 34 havingthickness which can vary across the width of the extruded slab. It willalso be clear that the gates 35 can be manually controlled byindividually threading each gate into and out to adjust the thickness ofany portion of the extrusion die and can, alternatively, be controlledby a controller 40 which can be a computer program to vary the thicknessof any portion of the extruded slab under remote control as desired.

A thermoplastic molding process is provided which includes selecting athermoplastic extrusion die 16 or 30 for the extrusion of athermoplastic slab, which extrusion die has an adjustable die gatemembers for varying the thickness of the extruded material in differentparts of the extruded slab. The process includes adjusting thethermoplastic extrusion die for various thickness of the extrudedmaterial passing therethrough in different parts of the extruded slaband then heating a thermoplastic material to a fluid and extruding aslab of fluid thermoplastic material through the selected and adjustedthermoplastic extrusion die. The thermoplastic slab is then trimmed anddirected onto a heated thermoplastic material into a thermoforming mold19 or 23 and molded in a molding apparatus 13 to form a part with avariable thickness in the part.

It should be clear at this time that a thermoplastic molding process andapparatus have been provided which allow for the thermoforming of a partwith a variable thickness with an extrusion die which can becontinuously controlled to vary the thickness of different parts of theextruded slab being molded and that the molding is accomplished whilethe thermoplastic slab is still heated to utilize the heat energy fromthe extrusion process. However, it should also be clear that the presentinvention is not to be considered limited to the forms shown which areto be considered illustrative rather than restrictive. For example,although the extruded material is described sometimes as a generallyflat plate slab, it is also described as follows: (i) containing heatenergy when delivered to the compression mold 13 to obviate reheating,(ii) having a variable thickness throughout its width, (iii) being a hotmelt when charged into the mold half 19 from the extruder 11, (iv) usinga plurality of gated plates 35 to vary the thickness across the width ofthe extruded material and in different parts of the extruded material,and finally (v) extruding molten thermoplastic material through theselected and adjusted extrusion die to achieve a variable thickness inthe part formed. Thus, the extruder generally provides a molten flow ofthermoplastic composite material through the dynamic die, gravitatingonto a mold half or lower mold in variable quantities in the verticalplane and across both horizontal directions on the mold.

The “extrusion-molding” process described above is ideal formanufacturing medium to large thermoplastic composite structuresreinforced with glass, carbon, metal or organic fibers to name a few.The extrusion-molding process includes a computer-controlled extrusionsystem that integrates and automates material blending or compounding ofthe matrix and reinforcement components to dispense a profiled quantityof molten composite material that gravitates into the lower half of amatched-mold, the movement of which is controlled while receiving thematerial, and a compression molding station for receiving the lower halfof the mold for pressing the upper half of the mold against the lowerhalf to form the desired structure or part. The lower half of thematched-mold discretely moves in space and time at varying speeds toenable the deposit of material more thickly at slow speed and morethinly at faster speeds. The thermoplastic apparatus 10 described aboveis one embodiment for practicing the extrusion-molding process.Unprocessed resin (which may be any form of regrind or pellettedthermoplastic or, optionally, a thermoset epoxy) is the matrix componentfed into a feeder or hopper of the extruder, along with reinforcementfibers greater than about one-half inch (½″) in length. The compositematerial may be blended and/or compounded by the extruder 11, and“intelligently” deposited onto the lower mold half 19 by controlling theoutput of the extruder 11 with the gates 35 and the movement of thelower mold half 19 relative to the position of the extruder 11, as willbe described below with the embodiments shown in FIGS. 6A and 6B. Inthose embodiments the lower section of the matched-mold is fastened on atrolley which moves discretly below the dynamic die. The lower sectionof the matched-mold receives precise amounts of extruded compositematerial, and is then moved into the compression molding station.

The thermoplastic matrix materials that may be utilized in theextrusion-molding processes to form the composite material includethermoplastic resins as understood in the art. The thermoplastic resinsthat may be utilized in accordance with the principles of the presentinvention may include any thermoplastic resin that can be melted andblended by the extruder 11. Examples of such thermoplastic resins areprovided in TABLE 1 with the understanding that the examples are notintended to be a complete list, and that other thermoplastic resins andmaterials may be utilized in producing the structural parts utilizingthe extrusion-molding system. Additionally the thermoplastic resins ofTABLE 1 may be used alone or in any combinations thereof. TABLE 1Thermoplastic Resins polyethylene polysulfone polypropylenepolyphenylene oxide polyvinyl chloride polybutylene terephthalatepolyvinylidene chloride polyethylene terephthlate polystyrenepolycyclohexane diethylene terephthalate styrene-butadiene- polybutylenenaphthalate acrylonitrile copolymer nylon 11 other polyesters used assoft segments nylon 12 thermotropic liquid crystal polymers nylon 6polyphenylene sulfide nylon 66 polyether ether ketones other aliphaticnylons polyether sulfones copolymers of aliphatic polyether imidesnylons further copolymerized with terephthalic acid or other aromaticdicarboxylic acids or aromatic diamines other aromatic polyamidespolyamide imides various copolymerized polyimides polyamidespolycarbonate polyurethane polyacetal polyether amidespolymethylmethacrylate polyester amides

Particular thermoplastic materials, including polypropylene,polyethylene, polyetheretherketone, polyesters, polystyrene,polycarbonate, polyvinylchloride, nylon, polymethyl, polymethacrylate,acrylic, polyurethane and mixtures thereof, have been especiallysuitable for the extrusion-molding process.

The fibers that serve as the reinforcement component for thethermoplastic composite materials generally include those materials thatmay be utilized to reinforce thermoplastic resins. Fiber materialssuitable for use in accordance with the principles of the presentinvention include, without limitation, glass, carbon, metal and naturalmaterials (e.g., flax, cotton), either alone or in combination. Otherfibers not listed may also be utilized as understood in the art.Although the diameter of the fiber generally is not limited, the fiberdiameter for molding larger structural parts generally ranges between 1and 20 μm. It should be understood, however, that the diameter of thefibers may be larger depending on a number of factors, includingstrength of structural part desired, density of fiber desired, size ofstructural part, etc. In particular, the effect of improvement ofmechanical properties is marked with a fiber having a diameter ofapproximately one (1) to approximately nine (9) μm.

The number of filaments bundled in the fiber also is not generallylimited. However, a fiber bundle of 10,000 to 20,000 filaments ormonofilaments is generally desired for handling considerations. Rovingsof these reinforcing fibers may be used after surface treatment by asilane or other coupling agent. To improve the interfacial bonding withthe thermoplastic resin, for example, in the case of a polyester resin,surface treatment may be performed by a thermoplastic film formingpolymer, coupling agent, fiber lubricant, etc. Such surface treatmentmay be performed in advance of the use of the treated reinforcing fibersor the surface treatment may be performed just before the reinforcingfibers are fed into the extruder in order to run the extrusion processto produce the molten thermoplastic composite without interruption. Theratio between the thermoplastic resin and fiber is not particularlylimited as it is possible to produce the thermoplastic composite andshaped articles using any ratio of composition in accordance with thefinal object of use. However, to provide sufficient structural supportfor the structural parts, as understood in the art, the content offibers is generally five percent (5%) to fifty percent (50%) by weight.It has been determined that the content of fibers is generally ten (10)to seventy (70) percent by weight, and preferably forty percent (40%) byweight to achieve the desired mechanical properties for the productionof larger articles.

The average fiber length of the fibers is greater than about one-halfinch (½″). However, typical structural parts produced by theextrusion-molding system 600 a utilize fiber lengths longer than aboutone inch. It should be noted that when the average fiber length is lessthan one inch, the desired mechanical properties for large articles isdifficult to obtain. Distribution of the fibers in the thermoplasticcomposite material is generally uniform so that the fibers andthermoplastic resin do not separate when melted and compressed. Thedistribution or disbursement of the fibers includes a process by whichthe fibers are dispersed from a single filament level to a level ofmultiple filaments (i.e., bundles of several tens of fibers). In oneembodiment, bundles of about five fibers are dispersed to provideefficiency and structural performance. Further, the “degree of combing”may be evaluated by observing a section of the structure by a microscopeand determining the ratio of the number of reinforcing fibers in bundlesof ten or more in all of 1000 or more observable reinforcing fibers(total number of reinforcing fibers in bundles of 10 or more/totalnumber of reinforcing fibers×100) (percent). Typical values produced bythe principles of the present invention result in not more thanapproximately sixty percent (60%), and generally below thirty-fivepercent (35%).

FIG. 6A is an exemplary schematic diagram of an extrusion-molding system600 a operable to form structural parts. The extrusion-molding system600 a is composed of a number of discrete components that are integratedto form structural parts from composite material. The components includea material receiving unit 602, a heater 618, an extruder 604, a dynamicdie 606, a trolley 608, a compression press 610, and a controller 612.Other supplemental components may also be included to form theextrusion-molding system 600 a.

The material receiving unit 602 may include one or more hoppers orfeeders 614 and 615 for receiving materials M1 and M2, respectively,that will be extruded to form a thermoplastic composite. It should beunderstood that additional feeders may be utilized to receive additionalmaterials or additives to formulate different compounds. In the instantexample, materials M1 and M2 represent the starting material i.e.,reinforced thermoplastic materials preferably in the form of pellets. M1and M2 may be the same or different reinforced thermoplastic material.The thermoplastic materials may be reinforced by fibers, such as glassor carbon fibers, as understood in the art. It should be furtherunderstood that non-thermoplastic material may be utilized in accordancewith the principles of the present invention.

A heater 618 preheats the thermoplastic materials M1 and M2. Theextruder 604 is coupled to the feeder channel 616 and operable to mixthe heated thermoplastic materials M1 and M2 via an auger 620. Theextruder 604 further melts the thermoplastic materials. The auger 620may be helical or any other shape operable to mix and flow the compositematerial through the extruder 604. An extruder output channel 622 iscoupled to the extruder 604 and is utilized to carry the compositematerial to a dynamic die 606.

The dynamic die 606 includes multiple flow control elements 624 a-624 n(collectively 624). The flow control elements 624 may be individualgates, valves, or other mechanisms that operate to control the extrudedcomposite material 625 from the dynamic die 606, where the extrudedcomposite material 625 a-625 n (collectively 625) varies in volumetricflow rates across a plane P at or below the flow control elements 624.The outputting of the different volumetric flow rates ranges betweenapproximately zero and 3000 pounds per hour. A more preferable range forthe volumetric flow rate ranges between approximately 2500 and 3000pounds per hour. In one embodiment, the flow control elements 624 aregates that are raised and lowered by separate actuators, such aselectrical motors, (e.g., stepper motors), hydraulic actuators,pneumatic actuators, or other actuator operable to alter flow of thecomposite material from the adjustable flow control elements 624,individually or collectively. The flow control elements 624 may beadjacently configured to provide for a continuous separating adjacentflow control elements 624. Alternatively, the flow control elements 624may be configured separately such that the composite material flowingfrom adjacent flow control elements 624 remains separated until thecomposite material spreads on a mold. It should be understood that theflow control elements 624 suitably may operate as a trimmer 17. In anembodiment of the invention, the molten composite material may bedelivered to an accumulator, placed between the extruder 604 and thedynamic die 606, from which the composite material may be delivered intoa lower mold using a plunger or other actuating mechanism.

The trolley 608 may be moved beneath the dynamic die 606 so that theextruded composite material 625 gravitates to or is deposited on a lowermold 626, which passes below the dynamic die 606 at a predeterminedvertical distance, the “drop distance” (d). The lower mold 626 definescavities 630 that are used to form a structural part. The extrudedcomposite material 625 is deposited 628 on the lower mold 626 to fillthe volume defined by the cavities 630 in the lower mold 626 and anupper mold 632 to form the composite part. In a two-axis controlledprocess, the composite material 625 a may be deposited on the lower mold626 at a substantially constant volumetric flow rate from the dynamicdie 606 or across a vertical plane (P), based on discrete movement andvariable speeds, to form the composite material layer 628 havingsubstantially the same thickness or volume along the vertical plane (P)to fill the cavities 630 in the lower and upper molds 626 and 632. In athree-axis controlled process, the composite material may be depositedon the lower mold 626 at different volumetric flow rates from thedynamic die 606 across the vertical plane (P) to form the compositematerial layer 628 having different thickness or volume along thevertical plane (P) to fill the cavities 630 in the lower and upper molds626 and 632. It should be understood that the two-axis controlledprocess may be utilized to deposit the composite material to molds thathave cavities 630 substantially constant in depth in the vertical planeand that the three-axis controlled process may be utilized to depositthe composite to molds that have cavities 630 that vary in depth.

The trolley 608 may further include wheels 634 that provide fortranslation along a rail 636. The rail 636 enables the trolley 608 toroll beneath the dynamic die 606 and into the press 610. The press 610operates to press the upper mold 632 into the lower mold 626. Eventhough the principles of the present invention provide for reduced forcefor the molding process than conventional thermoplastic moldingprocesses due to the composite material layer 628 being directlydeposited from the dynamic die 606 to the lower mold 626, the forceapplied by the press 610 is still sufficient to damage the wheels 634 ifleft in contact with the rail 636. Therefore, the wheels 634 may beselectively engaged and disengaged with an upper surface 638 of a base640 of the press 610. In an embodiment, the trolley 608 is raised byinflatable tubes (not shown) coupled thereto so that when the tubes areinflated, the wheels 634 engage the rails 636 so that the trolley 608 ismovable from under the die 606 to the press 610. When the tubes aredeflated, the wheels 634 are disengaged so that the body of the trolley608 is seated on the upper surface 638 of a base 640 of the press 610.It should be understood that other actuated structural components may beutilized to engage and disengage the wheels 634 from supporting thetrolley 608, but that the functionality to engage and disengage thewheels 634 is to be substantially the same. For example, the uppersurface 638 of the base 640 of the press 610 may be raised to contactthe base plate 642 of the trolley 608.

The controller 612 is electrically coupled to the various componentsthat form the extrusion-molding system 600. The controller 612 is aprocessor-based unit that operates to orchestrate the forming of thestructural parts. In part, the controller 612 operates to control thecomposite material being deposited on the lower mold 626 by controllingtemperature of the composite material, volumetric flow rate of theextruded composite material 625, and the positioning and rate ofmovement of the lower mold 626 via the trolley 608 to receive theextruded composite material 625. The controller 612 is further operableto control the heater 618 to heat the thermoplastic materials. Thecontroller 612 may control the rate of the auger 620 to maintain asubstantially constant flow of composite material through the extruder604 and into the dynamic die 606. Alternatively, the controller 612 mayalter the rate of the auger 620 to alter the volumetric flow rate of thecomposite material from the extruder 604. The controller may furthercontrol heaters (not shown) in the extruder 604 and the dynamic die 606.Based on the structural part being formed, a predetermined set ofparameters may be established for the dynamic die 606 to apply theextruded composite material 625 to the lower mold 626. The parametersmay be defined such that the flow control elements 624 may beselectively positioned such that the movement of the trolley 608 ispositionally synchronized with the volumetric flow rate of the compositematerial in accordance with the cavities 630 that the define thestructural part being produced.

The trolley 608 may further include a heater (not shown) that iscontrolled by the controller 612 and is operable to maintain theextruded composite material 625 in a heated or melted state. Thecontroller may, by varying the required speeds of the trolley, controlthe trolley 608 during extruded composite material 625 being applied tothe lower mold 626. Upon completion of the extruded composite material625 being applied to the lower mold 626, the controller 612 drives thetrolley 608 into the press 610. The controller then signals a mechanism(not shown) to disengage the wheels 634 from the track 636 as describedabove so that the press 610 can force the upper mold 632 against thelower mold 626 without damaging the wheels 634.

FIG. 6B is another exemplary block diagram of the extrusion-moldingsystem 600 a of FIG. 6A. The extrusion-molding system 600 b isconfigured to support two presses 610 a and 610 b that are operable toreceive the trolley 608 that supports the lower mold 626 to form thestructural part. It should be understood that two trolleys 608 may besupported by the tracks or rails 636 so as to provide for formingmultiple structural components by a single extruder 604 and dynamic die606. While wheels 634 and rails 636 may be utilized to provide movementfor the trolley 608 in one embodiment, it should be understood thatother movement mechanisms may be utilized to control movement for thetrolley 608. For example, a conveyer, suspension, or track drive systemmay be utilized to control movement for the trolley 608.

The controller 612 may be configured to support multiple structuralparts so that the extrusion-molding system 600 b may simultaneously formthe different structural parts via the different presses 610 a and 610b. Because the controller 612 is capable of storing parameters operableto form multiple structural parts, the controller 612 may simply altercontrol of the dynamic die 606 and trolleys 608 a and 608 b by utilizingthe parameters in a general software program, thereby providing for theformation of two different structural parts using a single extruder 604and dynamic die 606. It should be understood that additional presses 610and trolleys 608 may be utilized to substantially simultaneously producemore structural parts via a single extruder 604 and dynamic die 606.

FIG. 7 is an exemplary exploded view of the dynamic die 606 depositingthe extruded composite material 625 on the lower mold 626 as supportedby the trolley 608. As shown, the dynamic die 606 includes the multipleflow control elements 624 a-624 i. It should be understood that thenumber of flow control elements 624 may be increased or decreaseddepending upon the resolution or detail of the structural part beingformed. As shown, the flow control elements 624 are positioned atdifferent heights so as to provide more or less volumetric flow rate ofthe extruded composite material 625 associated with each flow controlelement 624. For example, flow control element 624 a is completelyclosed, so as to prevent composite material from being passed throughthat section of the dynamic die 606. The volumetric flow rate f_(a) istherefore zero associated with the closed flow control element 624 a.The flow control element 624 b is opened to form an aperture having aheight h₁, thereby providing a volumetric flow rate f_(b) of theextruded composite material 625 b. Similarly, the flow control element624 c is opened to form a larger aperture for the extruded compositematerial 625 c to be output at a higher volumetric flow rate f_(c) ontothe lower mold 626.

As indicated by the variation in shading of the extruded compositematerial 625 associated with each of the flow control elements 624, theflow control elements 624 may be dynamically adjusted based on thestructural part being formed via the lower and upper molds 626 and 632.Accordingly, based on the structural part being formed (e.g., deep drawover a certain region), the flow control elements 624 may be adjusted toalter the volumetric flow rates of the extruded composite material 625over finite regions of the lower and upper molds 626. In other words,based on the cavities 630 defined by the lower and upper molds 626 and632, the composite material layer 628 may be varied in thickness. Forexample, the composite material layer region 628 a is thinner thancomposite material layer region 628 b, which is thicker to sufficientlyfill the cavity 630 a, which has a deeper draft than other locations ofthe cavity 630 in the lower mold 626. In other words, the extrudedcomposite material layer 628 is dynamically altered based on the depthof the cavity 630 defined by the molds 626 and 632. In both the two- andthree-axis controlled processes capable of being performed on theextrusion-molding system 600 a, the extruded composite material layer628 may be dynamically altered in terms of thickness based on thevolumetric flow rate of the extruded composite material 625 and thespeed of travel of the trolley 608.

Depositing the extruded composite material onto the lower mold may beperformed by controlling the amount of extruded composite materialdeposited in two or three axes depending on the structural part beingproduced. For the two-axis control, the movement of the trolley may becontrolled along the axis of movement to deposit the extruded compositematerial in various amounts along the axis of deposit. For thethree-axis control, the output of the extruder may utilize a dynamic diethat includes flow control elements, thereby providing for differentvolumetric flow rates to be simultaneously deposited onto the lower moldalong the axis perpendicular to the axis of movement. It should beunderstood that other embodiments may provide for off-axis or non-axiscontrol to deposit the extruded composite material in specific locationson the lower mold.

By providing for control of the trolley and composite material beingapplied to the lower mold, any pattern may be formed on the lower mold,from a thick continuous layer to a thin outline of a circle or ellipse;any two-dimensional shape that can be described by discrete mathematicscan be traced with material. Additionally, because control of the volumeof composite material deposited on a given area exists,three-dimensional patterns may be created to provide for structuralcomponents with deep draft and/or hidden ribs, for example, to beproduced. Once the structural part is cooled, ejectors may be used topush the consolidated material off of the mold. The principles of thepresent invention may be designed so that two or more unique parts maybe produced simultaneously, thereby maximizing production efficiency byusing a virtually continuous stream of composite material.

Value-Added Benefits of the Extrusion-Molding Process

With the extrusion-molding system, large long-fiber reinforced plasticparts may be produced in-line and at very low processing costs. Featuresof the extrusion system provide for a reinforced plastic componentsproduction line that offers (i) materials flexibility, (ii) depositionprocess, (iii) low-pressures, and (iv) machine efficiency. Materialsflexibility provides for savings in both material and machine costs fromin-line compounding, and further provides for material propertyflexibility. The deposition process adds value in the materialdeposition process, which allows for more complicated shapes (e.g.,large draft and ribs), better material flow, and ease of inclusion oflarge inserts in the mold. The low-pressures is directed to reducedmolding pressures, which lessen the wear on both the molds and themachines, and locks very little stress into the structural parts. Themachine efficiency provides for the ability to use two or morecompletely different molds at once to improve the efficiency of theextrusion system, thereby reducing the required number of machines torun a production operation. Additionally, the material delivery systemaccording to the principles of the present invention may be integratedwith many existing machines.

Materials Flexibility

The extrusion-molding process allows custom composite blends to becompounded using several different types of resin and fiber. Theextrusion system may produce parts with several resins as describedabove. With traditional compression molding, pre-manufacturedthermoplastic sheets, commonly known as blanks that combine a resin withfibers and desired additives are purchased from a thermoplastic sheetproducer. These blanks, however, are costly because they have passedthrough several middle-men and are usually only sold in predeterminedmixtures. By utilizing the extrusion-molding process according to theprinciples of the present invention, these costs may be reduced by thein-line compounding process utilizing the raw materials to produce thestructural parts without having to purchase the pre-manufactured sheets.Labor and machine costs are also dramatically reduced because theextrusion-molding system does not require ovens to pre-heat the materialand operators to move the heated sheets to the mold. Since the operatorcontrols the compounding ratios as desired, nearly infinite flexibilityis added to the process, including the ability to alter properties whilemolding or to create a gradual change in color, for example. Also,unlike sheet molding, the extrusion-molding system does not require thematerial to have a melt-strength, giving the system added flexibility.In one embodiment, the extrusion-molding system may utilize thermosetresins to produce the structural parts. The extrusion-molding system mayalso use a variety of fiber materials, including carbon, glass and otherfibers as described above, for reinforcement with achievable fibervolume fractions of over 50 percent and fiber lengths of one to fourinches or longer with 85 percent or higher of the fiber length beingmaintained from raw material to finished part.

Deposition Process

The extrusion system, according to the principles of the presentinvention, allows for variable composite material lay-down; in regionsof the mold where more material is to be utilized for deep draft orhidden ribs, for example, thereby minimizing force utilized duringmolding and pressing. The variable composite material lay-down resultsin more accuracy, fuller molds, and fewer “short-shots” as understood inthe art than with typical compression molding processes. Variablelay-down also allows for large features to be molded on both sides ofthe structural part, as well as the placement of inserts or cores intothe structural part. Lastly, since the material has a relatively verylow viscosity as it is being deposited in a molten state onto the mold(as opposed to being pre-compounded into a sheet and then pressed into amold), fibers are able to easily enter ribs and cover large dimensionalareas without getting trapped or becoming undesirably oriented.

Low-Pressures

The thermoplastic composite material being deposited during theextrusion-molding process is much more fluid than that from a heatedpre-compounded sheet, thus allowing the thermoplastic composite materialto flow much easier into the mold. The fluidity of the compositematerial being deposited onto the mold results in significantly reducedmolding pressure requirements over most other molding processes. Pressesfor this process generally operate in the range of 100 pounds per squareinch, compared with 1,000 pounds per square inch of pressure used forcompression molding. This lower pressure translates to less wear,thereby reducing maintenance on both the molds and the press. Because ofthe lower pressures, instead of needing a steel tool that could costover $200,000, an aluminum mold, capable of 300,000 cycles, and may bemanufactured for as little as $40,000. Less expensive tooling also meansmore flexibility for future design changes. Since the thermoplasticresin is relocated and formed on the face of the mold under lowerpressures, less stress is locked into the material, thereby leading tobetter dimensional tolerance and less warpage.

Machine Efficiency

Because the extrusion-molding process may use two or more molds runningat the same time, there is a reduction in the average cycle time perpart, thus increasing productivity as the first mold set may be cooledand removed while a second mold is filled and compressed. Also, theextrusion-molding system utilizes minimal redundant components. In oneembodiment, the extrusion system utilizes a separate press for eachmold, but other equipment may be consolidated and shared between themold sets and may be easily modified in software to accommodate othermolds. The extrusion and delivery system 600 a further may be integratedinto current manufacturing facilities and existing compression molds andpresses may be combined.

FIG. 8A is an exemplary flow diagram describing the extrusion-moldingprocess that may be utilized to form articles or structural parts byusing either two- or three-axis control for depositing the compositematerial onto the lower mold 626. The extrusion-molding process startsat step 802. At step 804, the thermoplastic material is heated to formmolten thermoplastic material and blended with the fiber at step 802 toform a composite material. At step 708, the molten composite material isdelivered through the dynamic die to gravitate onto a lower mold 626.For the two-axis extrusion deposit process, a fixed output from the diemay be utilized. In a two-axis process, the movement of the trolley ismaintained at a constant speed. In a three-axis extrusion controlprocess, a dynamic die 606 may be utilized in conjunction with varyingtrolley or mold speeds. For both the two- and three-axis extrusioncontrol process, the lower mold 626 may be moved in space and time whilereceiving the composite material to conform the amount of compositematerial required in the cavity 630 defined by the lower and upper molds626 and 632 at step 810. At step 812, the upper mold 632 is pressed tothe lower mold 626 to press the composite material into the lower andupper molds 626 and 632. The process ends at step 814.

FIG. 8B is an exemplary flow diagram for producing structural partsutilizing the extrusion-molding system 600 a of FIG. 6A via thethree-axis control extrusion-molding process. The structural partproduction process starts at step 816. At step 818, thermoplasticmaterial is received. The thermoplastic material is heated at step 822.In one embodiment, the thermoplastic material is heated to a melted ormolten state. At step 820, fibers having a predetermined fiber lengthare received. At step 822, the fibers are blended with the heatedthermoplastic material to form a composite material. The fibers may belong strands of fiber formed of glass or other stiffening materialutilized to form large structural parts. For example, fiber lengths ofone-half inch (½″) up to four inches (4″) or more in length may beutilized in forming the structural parts.

The composite material is extruded at step 826. In the extrusionprocess, the auger 620 or other mechanism utilized to extrude thecomposite material is configured to substantially avoid damaging thefibers such that the original fiber lengths are substantially maintained(e.g., 85 percent or higher). For example, in the case of using a screwtype auger 620, the thread spacing is selected to be larger than thelength of the fibers, thereby substantially avoiding damaging thefibers.

At step 828, the extruded composite material 625 may be dynamicallyoutput at different volumetric flow rates across a plane to provide forcontrol of depositing the extruded composite material 625 onto the lowermold 626. The lower mold 626 may be positionally synchronized to receivethe extruded composite material 625 in relation to the differentvolumetric flow rates across the plane P at step 830. In an embodiment,the positional synchronization of the mold 626 is performed inaccordance with flow control elements 624 that are located at a height dabove the trolley 608, which may be translated at a substantiallyconstant or adjustable rate. For example, to deposit a constant or flatextruded composite material layer 628, the trolley 608 is moved at asubstantially constant rate, but to increase or decrease the volume ofthe extruded composite material layer 628, the trolley 608 may be movedat a slower or faster rate, respectively. At step 832, the extrudedcomposite material 625 that is formed into the extruded compositematerial layer 628 is pressed into the mold 626 to form thethermoplastic structural part. The structural part forming process endsat step 834.

FIG. 9 is an exemplary block diagram 900 of the controller 612 asconfigured to communicate with controllers operating within componentsof the extrusion system 600 a of FIG. 6A. The controller 612communicates with the various controllers for bidirectionalcommunication using digital and/or analog communication channels asunderstood in the art. The controllers operating within the componentsmay be processor based operating open or closed-loop control software asunderstood in the art and operate as slave computers to the controller612. Alternatively, the controllers may be non-processor basedcontrollers, such as analog or digital circuitry, that operate as slaveunits to the controller 612.

The feeder(s) 614 may include a speed and temperature controller 902that is operable to control speed and temperature of the feeder(s) 614for mixing the composite material M1 and fiber material M2. The feederspeed and temperature controller(s) 902 may be formed of single ormultiple controllers to control motor(s) and heater(s). The controller612 is operable to specify or command the velocity or rate andtemperature of the feeder(s) 614, while the speed and temperaturecontroller 802 of the feeder(s) 614 is operable to execute the commandsreceived by the controller 812. For example, based on the amount ofcomposite material being extruded via the dynamic die 606, thecontroller 612 may increase the rate of the materials M1 and M2 beingfed into the extruder 606.

The controller 612 is further in communication with the heatercontroller 904. The controller 612 may communicate control data to theheater controller 904 based on feedback data received from the heatercontroller 904. For example, if the temperature of the heater controller904 decreases during feeding operations, then the controller 612 mayissue commands via the control data 1018 to the heater controller 904 toincrease the temperature of the heater 618. Alternatively, the heatercontroller 904 may regulate the temperature utilizing a feedbackregulator loop as understood in the art to the temperature commanded bythe controller 612 and simply report the temperature to the controller612 for monitoring purposes.

The controller 612 is further in communication with an extruder speedand temperature controller 906, which provides control over the speed ofthe auger 620 and temperature of the extruder 604. The extruder speedand temperature controller 906 may be operable to control multipleheaters within zones of the extruder 604 and communicate thetemperatures of each heater to the controller 612. It should beunderstood that the extruder speed and temperature controller 906 may beformed of multiple controllers.

The controller 612 is further in communication with a dynamic diecontroller 908 that controls the flow control elements 624 of thedynamic die 606. The dynamic die controller 908 may operate to controleach of the flow control elements 624 collectively or individually.Alternatively, each flow control element 624 may be individuallycontrolled by separate controllers. Accordingly, the controller 612 mayoperate to issue commands to the dynamic die controller 908 to set theposition for each of the flow control elements 624 in an open-loopmanner. For example, a stepper motor may be utilized in an open-loopmanner. Actual position of each flow control elements 624 may becommunicated back to the controller 612 via the feedback data 1022 forthe controller 612 to utilize in controlling the positions of the flowcontrol elements 624.

The controller 612 is further in communication with a trolley controller910 that is coupled to the trolley 608 and is operable to controlposition of the trolley 608 and temperature of the lower mold 626. Thecontroller 612 may provide control signals 1018 to the trolleycontroller 910 that operates as a servo to drive the trolley 608 to thepositions commanded by the controller 612, which, in the case ofdepositing the extruded composite material 625 onto the lower mold 626,positions the lower mold 626 accordingly. Although the extrudedcomposite material layer 628 that is deposited onto the lower mold 626is molten at the time of deposition, the extruded composite materiallayer 628 deposited first tends to cool as the later extruded compositematerial 625 is being deposited. Therefore, the controller 612 maycommunicate control data 1018 to the trolley controller 910 to maintainthe temperature of the extruded composite material layer 628, either ata substantially constant temperature, based on time of deposition of theextruded composite material 625, and/or based on other factors, such asthermoplastic material M1 molten state temperature requirements.Feedback data 1022 may provide current temperature and status of theposition and velocity of the trolley 608 and temperature of the lowermold 626 so that the controller 612 may perform management andmonitoring functions.

The controller 612 is further in communication with a heat/coolcontroller 912, which is operable to control temperature of heatersand/or coolers for the extrusion-molding system 600 a. The heat/coolcontroller 912 may receive the control data 1018 from the controller 612that commands the heat/cool controller 912 to operate at a specific orvariable temperature based on a number of factors, such as thermoplasticmaterial M1, ambient temperature, characteristics of structural partbeing produced, production rates, etc. The heat/cool controller 912 maycontrol system-level heaters and coolers or component-level heaters andcoolers. Feedback data 1022 may provide current temperature and statusof the heaters and coolers so that the controller 612 may performmanagement and monitoring functions.

The controller 612 is further in communication with a press controller914, which is operable to control press operation and temperature of theupper mold 632. The press controller 914 may be a standard controllerthat the manufacturer of the press 610 supplies with the press 610.Similarly, the press controller 914 may include a temperature controllerto control the temperature of the upper mold 932. Alternatively, thetemperature controller may not be associated with the press controller914 provided by the manufacturer of the press 910. Feedback data 612 mayprovide current position and force of the press and temperature of theupper mold 632 so that the controller 612 may perform management andmonitoring functions.

The controller 612 is further in communication with an extraction toolcontroller 916 that is operable to control extraction operations on amolded structural component. In response to the controller 612 receivingnotification from the press controller 914 that the press 610 hascompleted pressing operations, the controller 612 may issue controlsignals 1018 to the extraction tool controller 916 to initiateextraction of the molded structural component. Accordingly, feedbackdata 1022 may be utilized to indicate current operation of theextraction tool. If the feedback data 1022 indicates that the extractiontool is having difficulty extracting the molded structural component, anoperator of the extrusion-molding system 600 a may be notified that aproblem exists with the extraction tool, the lower or upper molds 626and 632, the press 610, the heater or cooler of the upper or lower mold626 and 632, or other component or function of the extrusion-moldingsystem 600 a.

It should be understood that while the controller 612 may be configuredto be a master controller for each of the components of theextrusion-molding system 600 a, that the controller 612 may beconfigured to manage the components in a more distributed controllermanner. In other words, the controllers of the components may operate asmore intelligent controllers that use the parameters of the structuralparts being produced to compute operating and control parameters andless as servos that are commanded by the controller 612 to perform afunction. It should be further understood that the controller 612 may beprogrammed to accommodate different mechanical configurations of theextrusion-molding system 600 a. For example, if the extrusion-moldingsystem 600 a were configured such that the output of the extruder 606translated or otherwise moved relative to a stationary lower mold 626,which may or may not be coupled to a trolley 608, then the controller612 may be programmed to control the movement of the output of theextruder 606 rather than movement of the trolley 608.

FIG. 10 is an exemplary block diagram of the controller 612 of FIG. 6A.The controller 612 includes a processor 1002 coupled to a memory 1004and user interface 1006. The user interface 1006 may be a touch screen,electronic display and keypad, pen-based interface, or any other userinterface as understood in the art. The processor 1002 is furthercoupled to an input/output (I/O) unit and a storage unit 1010 thatstores information in databases or files 1012 a-1012 n (collectively,1012). The databases 1012 may be utilized to store control parametersfor controlling the extrusion-molding system 600 a, such as dataassociated with the lower and upper molds 626 and 632. The databases1012 additionally may be utilized to store data fed-back from theextrusion system 600 a during operation thereof.

The processor 1002 is operable to execute software 1014 utilized tocontrol the various components of the extrusion-molding system 600 a andto manage the databases 1012. In controlling the extrusion-moldingsystem 600 a, the software 1014 communicates with the extrusion-moldingsystem 600 a via the I/O unit 1008 and control bus 1016. Control data1018 is communicated via data packets and/or analog control signalsacross a control bus 1016 to the extrusion-molding system 600 a. Itshould be understood that the control bus 1016 may be formed of multiplecontrol busses, whereby each control bus is associated with a differentcomponent of the extrusion-molding system 600 a. It should be furtherunderstood that the control bus 1016 may operate utilizing a serial orparallel protocol.

A feedback bus 1020, which may be a single or multiple bus structure, isoperable to feedback data 1022 from the extrusion-molding system 600 aduring operation. The feedback data 1022 may be sensory data, such astemperature, position, velocity, level, pressure or any other sensoryinformation measured from the extrusion-molding system 600 a.Accordingly, the I/O unit 1008 is operable to receive the feedback data1022 from the extrusion-molding system 600 a and communicate thefeedback data 1022 to the processor 1002 to be utilized by the software1014. The software 1014 may store the feedback data in the database 1012and utilize the feedback data 1022 to control the components of theextrusion-molding system 600 a. For example, in the case of thetemperature of the heater being fed-back by the heater controller 904 tothe controller 612, if the temperature of the heater 618 becomes toolow, then the controller 612 may issue a command via the control data1018 to the heater 618 to increase the temperature thereof. Thecontroller 612 or component (e.g., heater) may include an automaticcontrol system as understood in the art for performing the control andregulation of the component.

In operation, the controller 612 may store control parameters forproducing one or more structural parts by the extrusion-molding system600 a. For example, data associated with parameters of the molds 626 and632, such as dimensions of the cavities 630, may be stored in thedatabase 1012. By storing multiple sets of parameters for variousstructural parts, the extrusion-molding system 600 a may be utilized toform the structural parts substantially simultaneously. The processor1002 may execute the software 1014 with the different sets of parametersin parallel to form the structural parts substantially simultaneously.That is, when one structural part is being pressed, another may beformed via the dynamic die 606 by applying the extruder compositematerial 625 onto the lower mold 626.

FIG. 11 is an exemplary block diagram of the software 1014 that isexecuted by the processor 1002. A system manager 1100 is operable tomanage various aspects of the controller 612. The system manager 1100interfaces with an operator interface 1102, system drivers 1104, and adatabase manager 1106.

The operator interface 1102 is utilized to provide an interface for anoperator of the extrusion-molding system 600 a to control theextrusion-molding system 600 a manually or establish programs and/orprofiles for producing structural parts. The operator interface 1102communicates with a program selector 1108, which, when previouslyprogrammed, allows the operator to select programs for producing thestructural parts. For example, a program that is established to producea pallet may be selected via the operator interface 1102 by an operatorso as to control the extrusion-molding system 600 a to produce thepallet as defined by a designer of the pallet in accordance with thelower and upper molds 626 and 632. In one embodiment, the programselector 1108 merely selects a generic program that produces specificstructural parts by controlling the extrusion-molding system 600 a byutilizing a specific sets of parameters for controlling the componentsaccordingly. The program selector 1108 may communicate with a parameterselector/editor 1110 that allows the operator to select a particular setof parameters to form a particular structural part and/or edit theparameters to alter the process for forming the structural part. Theparameter selector/editor 1110 may interface with the database manager1106 for selecting a particular set of parameters from a variety ofdifferent parameter datafiles available for the controller 612 to drivethe components of the extrusion-molding system 600 a to form differentstructural parts. For example, the database manager 1106 may have accessto a set of parameters for producing a pallet, I-beam, backboard, etc.It should be understood that each of the components of theextrusion-molding system 600 a may be controlled by generic drivers andthat the parameters selected for producing a structural part may alterthe behavior of each of the components of the extrusion-molding system600 a accordingly.

The system drivers 1104 may be utilized to integrate with the componentsof the extrusion-molding system 600 a as understood in the art. Forexample, individual system drivers 1104 may be utilized to control thefeeders 614, heater 618, extruder 604, dynamic die 606, trolley 608, andpress 610. The system drivers 1104 may be customized by the operator ofthe extrusion-molding system 600 a or be a generic driver provided by amanufacturer of a particular component, such as the press 610. Duringoperation of the extrusion-molding system 600 a producing a structuralpart, the system drivers 1104 may utilize the parameters selected toproduce the structural part to drive the components of theextrusion-molding system 600 a.

In controlling the components of the extrusion-molding system 600 a, adatabase 1012 and status alert feedback manager 1114 are utilized toprovide feedback control for each of the components of theextrusion-molding system 600 a. For example, the heater 618 may feedbackthe actual temperature via a temperature sensor (not shown). Based onthe measured temperature of the heater 618, a system driver 1104utilized to control the heater 618 may increase or decrease thetemperature of the heater 618 in accordance with the actual temperaturemeasurement. Accordingly, other sensors may be utilized to feedbacktemperature, pressure, velocity, weight, position, etc., of eachcomponent and/or composite material within the extrusion-molding system600 a. In the case of a critical failure of a component, alerts may befed-back to the controller 612 and detected by the status alert feedbackmanager 1114. If an alert is deemed to be a major failure, the systemdrivers 1104 may shut down one or more components of theextrusion-molding system 600 a to prevent damage to hardware or personalinjury to an operator. In response to such an alert, the system manager1100 may trigger the operator interface 1102 to display the failure andprovide notice as to corrective actions or otherwise.

FIG. 12 is an exemplary schematic of the flow control elements 624 a-624f and lower mold 626, which is sectioned into a grid 1202. The gridspacings are defined by the flow control elements 624 along the y-axis(identified as spacings 1-5) and defined by spacings a-e along thex-axis. It should be understood that a higher resolution for the gridmay be attained by utilizing more flow control elements 624 along they-axis and defining smaller spacings along the x-axis. Depending uponthe particular structural part being formed, higher or lower resolutionsmay be desired and parameters established by the operator to define thehigher or lower resolutions may be stored in the controller 612 via thedatabase manager 1106 for use in producing the structural parts.

TABLES 2-10 are exemplary data tables that are utilized to control thecomponents of the extrusion-molding system 600 a. Specifically, thetables provide for the control data 1018 for controlling the componentsand feedback data 1022 received by the controller 612 from thecomponents. TABLE 2 provides for control of the feeders 614 that areused to feed thermoplastic composite material M1, fiber material M2, andany other materials (e.g., color) to form the structural parts. Asshown, the control data 1018 includes the rate that each feeder 614 isdelivering material to the extrusion-molding system 600 a and thefeedback data 1022 includes the level of the material currently in eachfeeder 614. During operation of the extrusion-molding system 600 a, therate of the material being delivered from the feeder 614 is controlledand level of the material in the feeders 614 is measured, the operatormay be notified of the level of the material in response to the in thefeeder 614 reaching a minimum amount so that the operator may applyadditional material to the feeder 614. TABLE 2 Material Feeders ControlData Feedback Data Rate of Feed Material 1 Level of Material 1 Rate ofFeed Material 2 Level of Material 2 Rate of Feed Material 3 Level ofMaterial 3 . . . . . . Rate of Feed Material n Level of Material n

TABLE 3 is an exemplary table that provides for temperature control forheaters in the extruder 604. In the case that the extruder 604 isdefined as having seven temperature zones 1-n, the temperatures for eachzone may be set by the extruder temperature control being defined asbeing set to heat or cool, on or off, and/or a specific temperature (notshown). The feedback data 1022 may include the actual temperature ofeach zone of the extruder 604. Accordingly, temperature sensors areintegrated into each zone of the extruder 604 and the temperaturessensed are fed-back via the feedback bus 1020 to the controller 612 forfeedback control. TABLE 3 Extruder Temperature Control Control DataExtruder Temperature Zone Control On/Off Feedback Data 1 Heat/CoolOn/Off Actual Temp 2 Heat/Cool On/Off Actual Temp 3 Heat/Cool On/OffActual Temp . . . . . . . . . . . . 7 Heat/Cool On/Off Actual Temp

TABLE 4 is an exemplary table that provides for speed control for amotor (not shown) driving the auger 620 operating in the extruder 604.The control data 1018 includes a speed control setting to drive themotor. Actual speed and load of the motor are fed-back via the feedbackdata 1022 to the system driver 1104 utilized to control the rate of theauger 620 extruder 604 via the control data 1018. TABLE 4 Extruder MotorControl Control Data Feedback Data Speed Control Signal Actual Speed ofMotor Actual Load of Motor

TABLE 5 defines the temperature control for heaters in the dynamic die606. The control data 1018 may be defined by zones 1-n within thedynamic die 606. Similar to the temperature control of the extruder 604,the heater 618 may include heating and cooling controls and/or on andoff settings for controlling and/or regulating the temperature of thedifferent zones within the dynamic die 606. Accordingly, the feedbackdata 1022 may include the actual temperature for each of the zoneswithin the dynamic die 606 for control thereof. TABLE 5 Dynamic DieTemperature Control Control Data Dynamic Die Zone Temp Control On/OffFeedback Data 1 Heat/Cool On/Off Actual Temp 2 Heat/Cool On/Off ActualTemp 3 Heat/Cool On/Off Actual Temp . . . . . . . . . . . . N Heat/CoolOn/Off Actual Temp

TABLE 6 is an exemplary table for control of the flow control elements624 of the dynamic die 606. As shown, the control data includes flowcontrol elements 1-n and positions for each flow control element 624ranging from 1-m. It should be understood that the flow control elements624 may have a nearly infinite number of positions. However, forpractical purposes, the flow control element positions are typically setto have certain predetermined positions, such as each quarter-inchranging from zero to six inches, for example. In controlling thepositions of the flow control elements 624, a stepper motor or othertype of motor may be utilized. Accordingly, the feedback data 1022 forthe flow control elements 624 include the current positions of the flowcontrol elements 624 so that any deviation of position between thecontrol data 1018 communicated by the controller 612 to the dynamic die606 may be corrected by a feedback loop via the feedback data 1022 asunderstood in the art. TABLE 6 Dynamic Die Flow Control Element ControlControl Data Flow Control Element Position Feedback Data 1 Position 1-mCurrent Position 2 Position 1-m Current Position 3 Position 1-m CurrentPosition . . . . . . . . . N Position 1-m Current Position

TABLE 7 is an exemplary table that provides for temperature control forthe lower mold 626. It should be understood that a similar table may beutilized to control the temperature of the upper mold 632. As shown, thelower mold 626 may be segmented into a number of zones 1-n, whereheaters and/or coolers may be applied to each zone to heat and cool thelower mold 626 as commanded by the control data 1018. Accordingly,feedback data 1022 may provide for the actual temperature of the lowermold 626 so that feedback control may be performed by the controller 612to regulate the temperature of the lower mold 626. For example, as theextruded composite material 625 is applied to the lower mode 626, thetemperature of the lower mold 626 may be regulated across the zones toregulate the temperature of the extruded composite material layer 628based on time and other factors as the composite material is depositedonto the lower mold 626 and until the structural part is removed fromthe molds 626 and 632. TABLE 7 Heat/Cool Mold Control Control Data MoldTemp Zone Control On/Off Feedback Data 1 Heat/Cool On/Off Actual MoldTemp 2 Heat/Cool On/Off Actual Mold Temp 3 Heat/Cool On/Off Actual MoldTemp 4 Heat/Cool On/Off Actual Mold Temp . . . . . . . . . . . . NHeat/Cool On/Off Actual Mold Temp

TABLE 8 is an exemplary table that provides exemplary control parametersfor controlling the trolley 608. As shown, the control data 1018includes position, speed, and lift control for the trolley 608. Itshould be understood that additional control data 1018 may be includedto control motion of the trolley 608. For example, acceleration,rotation or angular position, or other dynamic control data may beutilized to move or synchronize the trolley 608 to properly align thelower mold 626 with respect to the application of the extruded compositematerial 625 being deposited or gravitated onto the lower mold 626. Thefeedback data 1022 for the trolley 608 may include actual position andcurrent speed of the trolley 608. The lift control data may be utilizedto engage and disengage the wheels 634 of the trolley 608 both duringdepositing of the extruded composite material 625 to the lower mold 626and pressing the extruded composite material layer 628 into the molds626 and 632 via the press 610, respectively. The actual position of thelift may be fed-back so as to ensure that the press 610 is not activateduntil the wheels 634 are disengaged via the lift mechanism (e.g., airtubes). TABLE 8 Trolley Control Control Data Feedback Data PositionControl Data Actual Position of Trolley Speed Control Data Current Speedof Trolley Lift Control Data Actual Position of Lift

TABLE 9 is an exemplary table that provides for control of the press610. The control data 1018 may include lock control data and cycle presstime. The feedback data 1022 may include position of the trolley 608 inthe press 610 and position of the press platen. Other control andfeedback parameters additionally may be included to control the press.For example, temperature control of the upper mold 632, force of thepress 610, etc., may also be included. TABLE 9 Press Control ControlData Feedback Data Lock Control Data Trolley Position in Press CyclePress Time Position of Press Platen

TABLE 10 provides an exemplary table for control of an extraction tool(not shown) for extracting a formed structural part from the molds 626and 632 after completion of the pressing and, optionally, coolingprocesses in forming the structural part. The control data 1018 mayinclude a start extraction cycle and feedback data 1022 may include asingle extraction tool position. It should be understood that multipleextraction tools or elements of an extraction tool may be utilized andother sensory feedback data may be sensed and fed-back to the controller612. TABLE 10 Extraction Tool Control Control Data Feedback Data StartExtraction Cycle Extraction Tool Position

FIG. 13 is a top view of the flow control elements 624 a-624 i asaligned to deposit the composite material onto the lower mold 626 ofFIG. 6A. As shown, the flow control elements 624 are positioned alongthe y-axis, which provides for three-axis control for depositing theextruded composite material 625 onto the lower mold 626. Accordingly,the x-axis control for depositing the extruded composite material 625may be provided by control of the movement of the trolley 608 atdifferent speeds below the flow control elements 624, the y-axis controlfor depositing the extruded composite material 625 may be provided bythe adjustment of the flow control elements 624, and the z-axis controlfor depositing the extruded composite material 625 may result fromcontrolling the deposition of the extruded composite material 625 alongthe x- and y-axes.

Control for depositing the extruded composite material 625 along the x-,y-, and z-axes may be performed using a variety of techniques,including: (1) controlling the volumetric flow rate of the compositematerial from the extruder 604 via the rate of rotation of the auger620; (2) controlling the rate of movement of the trolley 608 in a singleaxis; (3) controlling the aperture of the output of the extruder 604having a single flow control element 624 or multiple flow controlelements 624 operating uniformly; (4) individually controlling themultiple flow control elements 624; and (5) controlling motion of thetrolley 608 in multiple axes. Each of these techniques assume that othervariables are held constant. For example, technique (1) assumes that theoutput aperture of the extruder 604 is fixed and that the trolley 608travels at a constant rate below the output aperture. Technique (2)assumes that the volumetric flow rate of the composite material from theextruder 604 is constant and that the output aperture of the extruder604 is fixed. It should be understood, however, that the techniques maybe combined to provide additional control of the placement of theextruded composite material 625 onto the lower mold 626 as discussedwith regard to FIG. 6A, where techniques (1), (2), and (4) are combined.Technique (5) includes providing not only x-axis and y-axis control overlower mold 626, but also z-axis and rotation about any number of axes.By providing such control over the lower mold 626 using technique (5), avariety of structural parts may be formed that may not be possibleotherwise. In sum, the overall computer control of the various elementsof the inventive process serves a critical role in the coordination ofthe extrusion process and the production of a desired part and theoverall operability of the process.

Finally, rather than controlling movement of the lower mold 626, theextruded composite material 625 may be deposited onto a stationary ormoving lower mold 626 using moving output apertures from the extruder604. For example, output apertures traveling along rails or othermechanical structure may be controlled to deposit the composite materialin specific locations on the lower mold 626. An analogy for such amechanism is a laser jet printer.

Referring again to FIG. 13, the flow control elements 624 are shown inrelation to the lower mold 626 as it passes under the dynamic die 606and the numbers of the right side correspond with the position of thetrolley 608 in inches as it passes under the dynamic die 606. The lowermold 626 starts ten inches into the trolley 608 due to the lower mold626 being smaller than the trolley 608. TABLES 11-12 are exemplarytables that provide parameters for speed and gate control for the flowcontrol elements 624. The parameters may be utilized to produce thepallet utilizing the extrusion-molding system 600 a. TABLE 11 TrolleySpeed Control Parameters End Position Zone Control (%) Rate (ft/min)Start Position (inches) (inches) 1 0.50 6.67 0.0 10.0 2 2.00 1.67 10.015.0 3 1.00 3.33 15.0 27.0 4 2.00 1.67 27.0 33.0 5 1.00 3.33 33.0 45.0 62.00 1.67 45.0 50.0

TABLE 12 Flow Control Element Parameters Height Start Position EndPosition Gate Zone (inches) (inches) (inches) 1 1 0.00 0.0 50.0 2 1 0.000.0 10.0 2 2 1.00 10.0 15.0 2 3 0.50 15.0 27.0 2 4 1.00 27.0 33.0 2 50.50 33.0 45.0 2 6 1.00 45.0 50.0 3 1 0.00 0.0 10.0 3 2 0.50 10.0 15.0 33 0.00 15.0 27.0 3 4 0.50 27.0 33.0 3 5 0.00 33.0 45.0 3 6 0.00 45.050.0 4 1 0.00 0.0 10.0 4 2 0.50 10.0 15.0 4 3 0.00 15.0 27.0 4 4 0.5027.0 33.0 4 5 0.00 33.0 45.0 4 6 0.00 45.0 50.0 5 1 0.00 0.0 10.0 5 21.00 10.0 15.0 5 3 0.50 15.0 27.0 5 4 1.00 27.0 33.0 5 5 0.50 33.0 45.05 6 1.00 45.0 50.0 6 1 0.00 0.0 10.0 6 2 0.50 10.0 15.0 6 3 0.00 15.027.0 6 4 0.50 27.0 33.0 6 5 0.00 33.0 45.0 6 6 0.00 45.0 50.0 7 1 0.000.0 10.0 7 2 0.50 10.0 15.0 7 3 0.00 15.0 27.0 7 4 0.50 27.0 33.0 7 50.00 33.0 45.0 7 6 0.00 45.0 50.0 8 1 0.00 0.0 10.0 8 2 1.00 10.0 15.0 83 0.50 15.0 27.0 8 4 1.00 27.0 33.0 8 5 0.50 33.0 45.0 8 6 1.00 45.050.0 9 1 0.00 0.0 50.0

TABLES 11 and 12 provide for the positional synchronization between theflow control elements 624 and the movement of the trolley 608. Byorchestrating the movement between the two components (i.e., dynamic die606 and trolley 608), the extruded composite material 625 may bedeposited at positions along the lower mold 626 as specified by thevolume of the cavities 630 of the lower and upper molds 626 and 632. Inother words, the extruded composite material 625 is deposited onto thelower mold 626 to form the extruded composite material layer 628 thickenough to fill the cavities 630 of the lower and upper molds 626 and632, thereby providing the ability to form deep drafts and hidden ribsin certain locations of structural parts.

FIG. 14 is an exemplary perspective top view of a corner of a pallet1400 produced by the extrusion-molding system 600 a of FIG. 6A. Asshown, the draft or depth d₁ of the base 1402 of the pallet 1400 isshallower than the depth d2 of a foot 1404 of the pallet 1400. Bycontrolling the deposition of the extruded composite material 625 ontothe lower mold 626 utilizing the principles of the present invention,large structural parts having features, such as the foot 1404, having adeeper draft d₂ in specific regions of the structural parts may beformed using stiffener material M2 (e.g., long-strand fibers).

FIGS. 15A and 15B are an exemplary perspective bottom and top views,respectively, of a platform 1500 having hidden ribs 1502 a-1502 e(collectively 1502). As shown, the hidden ribs 1502 are variable inheight, but have a definite volume over one or more zones. Therefore, bydepositing more extruded composite material 625 over the zones havingthe hidden ribs 1502 and less extruded composite material 625 over thezones without the hidden ribs 1502. Because the platform 1500 is formedas a single molded composite structure using the extrusion-moldingsystem 600 a, the platform 1500 has fewer weaknesses in the structurecompared to a platform that is formed of multiple parts.

Insertion Techniques

In addition to forming structural parts using composite material havingfibers blended therein to provide strength in forming large parts, somestructural parts further are structurally improved by having othercomponents, such as attachments, fasteners, and/or stiffeners, insertedor embedded in certain regions. For example, structural parts that areto provide interconnectivity may utilize metallic parts extending fromthe composite material to provide strong and reliable interconnections.One such structural part is a portion of a floor covering 1600 for anice rink, as depicted in FIG. 16A. The floor covering 1600 includes thethermoplastic material 1602, which may be formed of the thermoplasticmaterial M1 and fibers M2, and a fastener 1604, which is formed ofmetal.

In forming the floor covering 1600, the fastener 1604 is positioned orconfigured in the lower mold 608 so that the extruded composite materiallayer 628 forms a bond layer 1606 with the fastener 1604 to maintain theposition thereof. To further secure the fastener 1604 to the floorcovering 1600, holes (not shown) may be included in the fastener 1604 toallow the extruded composite material layer 628 to fill in the holes.During the formation process, actuators may be configured in the lowermold 626 to maintain the position of the fastener 1604 during theextrusion-molding process and released via the controller 612 while theextruded composite material layer 628 is still in molten form. It shouldbe understood that the fastener 1604 alternatively may be configured inthe upper mold 632.

FIG. 16B is an exemplary portion of a backboard 1610 that is often usedby paramedics. The backboard 1610 is formed of composite material 1612and includes an insert 1614 encapsulated in the composite material 1612.The insert 1614 may be a carbon fiber tube so that the backboard 1610may be stiffened, lightweight, and x-ray transparent. In encapsulatingthe insert, the lower mold 626 may have actuators or simple pinsmaintain the insert 1614 in place while the extruded composite materiallayer 628 forms a bond layer 1616 therewith. Again, while the extrudedcomposite material layer 628 is in a molten state, the actuators and/orpins may be released such that the extruded composite material layer 628fills in any voids left from the actuators or pins. It should beunderstood that the insert 1614 may be substantially any material basedon the particular application or structural part being formed.

FIG. 17 is an exemplary flow diagram 1700 describing the operations forembedding or inserting an insert, such as a fastener, support, or otherelement, into a structural part utilizing the extrusion-molding system600 a of FIG. 6A. The insertion process starts at step 1702. At step1704, the insert is configured in either the lower or upper mold 626 or632. At step 1706, the molten extruded composite material 625 isdeposited on the lower mold 626. The extruded composite material isformed about at least a portion of the insert at step 1708 to secure theinsert into the structural part being formed. In one embodiment, theinsert is encapsulated or completely embedded in the extruded compositematerial 625 (see, for example, FIG. 16B). Alternatively, only a portionof the insert is embedded in the extruded composite material 625 so thata portion extends from the structural part.

At step 1710, if any supports are used to configure the insert in thelower 626 or upper 632 mold, then the supports are removed. Thesupports, which may be actuator controlled, simple mechanical pins, orother mechanism capable of supporting the insert during deposition ofthe extruded composite material 625 onto the lower mold 626, are removedbefore the extruded composite material layer 628 is hardened at step1712. The extruded composite material layer 628 may be hardened bynatural or forced cooling during pressing, vacuuming, or other operationto form the structural part. By removing the supports prior to theextruded composite material layer 628 being hardened, gaps produced bythe supports may be filled in, thereby leaving no trace of the supportsor weak spots in the structural part. At step 1714, the structural partwith the insert at least partially embedded therein is removed from themold 626 and 632. The insertion process ends at step 1716.

In another embodiment of the invention, an insert is encapsulated by aprocess of the claimed invention. In a manner analogous to the processdescribed in FIG. 17, an insert, such as a fastener, support, or otherelement, may be encapsulated with extruded thermoplastic materialutilizing the claimed extrusion-molding system. In other embodiments ofthe invention, multiple layers of material of varying thickness may bedeposited one on top of the other utilizing the claimedextrusion-molding system. Specifically, a first layer of thermoplasticmaterial is extruded into a lower mold, following which a second layerof the same or different thermoplastic material is layered on top of thefirst layer. In certain embodiments of the invention, an insert may beplaced on top of the first extruded layer prior to or instead oflayering the first layer with a second extruded layer. This form of“layering” can facilitate the formation of a structure having multiplelayers of thermoplastic material, of the same or different composition,and layers of different inserted materials.

The foregoing description is of a preferred embodiment for implementingthe invention, and the scope of the invention should not be limited bythis description. The scope of the present invention is instead definedby the following claims.

1. A method for forming an article from thermoplastic material andfiber, said method comprising: heating thermoplastic material to form amolten thermoplastic material for blending with the fiber; blending themolten thermoplastic material with the fibers to form a molten compositematerial having a concentration of fiber by weight; extruding the moltencomposite material to form a flow of composite material gravitating ontoa lower portion of a mold for forming the article; moving the lowerportion of the mold in space and time while receiving the flow ofcomposite material to deposit a predetermined quantity of moltencomposite material thereon conforming to mold cavities of the lower andan upper portion of the mold; and pressing the upper portion of the moldagainst the predetermined quantity of molten composite material andclosing on the lower portion of the mold to form the article.
 2. Themethod according to claim 1, further comprising controlling the flow ofcomposite material to vary the quantity of molten composite materialbeing delivered to the lower portion of the mold.
 3. The methodaccording to claim 1, wherein said blending includes blending the moltenthermoplastic material with the fibers being between approximately atleast one-half and approximately four inches in length.
 4. The methodaccording to claim 1, wherein said blending forms a molten compositematerial having a concentration of fiber of approximately at least tenpercent by weight.
 5. The method according to claim 1, wherein saidmoving of the lower portion of the mold forms a predetermined quantityof molten composite material of varying thickness on the mold.
 6. Themethod according to claim 1, wherein said moving of the lower portion ofthe mold is along a single axis.
 7. The method according to claim 1,wherein said extruding produces a molten composite material having aminimum of approximately 85 percent of unbroken fibers.
 8. The methodaccording to claim 1, wherein the gravitating flows the compositematerial with a volumetric flow rate substantially the same onto thelower portion of the mold.
 9. The method according to claim 1, whereinthe gravitating flows the composite material with different volumetricflow rates onto the lower portion of the mold.
 10. The method accordingto claim 1, further comprising controlling said extruding to vary thevolumetric flow rate of the molten composite material being gravitatedonto the lower portion of the mold.
 11. The method according to claim 1,wherein the gravitating of the molten composite material is performeddirectly onto the lower portion of the mold.
 12. The method according toclaim 1, wherein the molten composite material is extruded on to aninsert contained within the lower portion of the mold.
 13. The methodaccording to claim 12, wherein the insert is partially embedded withinthe thermoplastic material.
 14. The method according to claim 12,wherein the insert is completely embedded within the thermoplasticmaterial.
 15. The method according to claim 12, wherein the insert isencapsulated with thermoplastic composite material.
 16. The methodaccording to claim 1, wherein a first layer of thermoplastic compositematerial is extruded into the lower portion of the mold.
 17. The methodaccording to claim 16, wherein a second layer of thermoplastic materialis layered on top of the first layer.
 18. The method according to claim16, wherein an insert is placed on the first layer.
 19. The methodaccording to claim 18, wherein said insert is partially embedded withinthe first layer.
 20. The method according to claim 18, wherein saidinsert is completely embedded within the first layer.
 21. The methodaccording to claim 18, wherein a second layer of thermoplastic materialis layered on top of the insert.
 22. A system for forming an articlefrom thermoplastic material and fiber, said system comprising: a heateroperable to pre-heat reinforced thermoplastic material to form a moltenthermoplastic material; an extruder coupled to the heater and operableto melt and blend the molten thermoplastic material with the fiber toform a flow of composite material for gravitating onto a lower portionof a mold to form the article; a movable structure coupled to the lowerportion of the mold and operable to be moved in space and time whilereceiving the flow of composite material to deposit a predeterminedquantity of molten composite material thereon conforming to moldcavities of the lower and an upper portion of the mold; and a presscoupled to the upper portion of the mold and capable of receiving saidmovable structure with the lower portion of the mold, said pressoperable to press the upper portion of the mold against thepredetermined quantity of molten composite material on the lower portionof the mold to form the article.
 23. The system according to claim 22,further comprising a dynamic die having at least one flow controlelement and operable to control the flow of composite material in avaried amount of molten composite material being delivered to the lowerportion of the mold.
 24. The system according to claim 22, wherein saidextruder includes an auger having a thread spacing large enough to blendthe molten thermoplastic material with the fibers being betweenapproximately one and approximately four inches in length.
 25. Thesystem according to claim 22, wherein the blended molten compositematerial has a concentration of fiber of at least approximately tenpercent by weight.
 26. The system according to claim 22, furthercomprising a controller coupled to said moveable structure and operableto move of said moveable structure to position the lower portion of themold to form a predetermined quantity of molten composite material ofvarying thickness on the mold.
 27. The system according to claim 22,wherein said moveable structure includes wheels operable to move themoveable structure.
 28. The system according to claim 22, wherein saidextruder includes an auger operable to produce a molten compositematerial having a minimum of approximately 85 percent of unbrokenfibers.
 29. The system according to claim 22, further comprising a diecoupled to said extruder and operable to gravitate the flow of thecomposite material with a volumetric flow rate substantially the sameacross a plane onto the lower portion of the mold.
 30. The systemaccording to claim 22, further comprising a dynamic die coupled to saidextruder and operable to gravitate the composite material with differentvolumetric flow rates across a plane onto the lower portion of the mold.31. The system according to claim 22, further comprising a controllercoupled to said extruder and operable to vary the volumetric flow rateof the molten composite material from the extruder and gravitate themolten composite material onto the lower portion of the mold.
 32. Thesystem according to claim 31, wherein said controller moves said movablestructure directly below said extruder for gravitating the extrudedcomposite material onto the lower portion of the mold.
 33. A system forforming an article from thermoplastic material and fiber, said systemcomprising: means for heating thermoplastic material to form a moltenthermoplastic material for blending with the fiber; means for blendingthe molten thermoplastic material with the fibers to form a moltencomposite material having a concentration of fiber by weight; means forextruding the molten composite material to form a flow of compositematerial gravitating onto a lower portion of a mold for forming thearticle; means for moving the lower portion of the mold in space andtime while receiving the flow of composite material to deposit apredetermined quantity of molten composite material thereon conformingto mold cavities of the lower and an upper portion of the mold; andmeans for pressing the upper portion of the mold against thepredetermined quantity of molten composite material and closing on thelower portion of the mold to form the article.
 34. The system accordingto claim 33, further comprising means for controlling the flow ofcomposite material to vary the quantity of molten composite materialbeing delivered to the lower portion of the mold.
 35. The systemaccording to claim 33, further comprising means for controlling saidmeans for extruding to vary the volumetric flow rate of the moltencomposite material being gravitated onto the lower portion of the mold.36. An article formed of an extruded composite material comprising athermoplastic material and having a concentration of at least 10 percentby weight of fiber having lengths of at least one-half inch.
 37. Thearticle according to claim 36, further comprising hidden ribs.
 38. Thearticle according to claim 36, wherein the article is a single compositematerial having structural features of different depths.
 39. The articleaccording to claim 38, wherein the different depths of the structuralfeatures are greater than approximately one inch.
 40. The articleaccording to claim 36, wherein the concentration of weight of fiber forthe composite material is at least 30 percent.
 41. The article accordingto claim 36, wherein the length of fiber is at least approximately threeinches.
 42. An article formed of an extruded composite materialcomprising a thermoplastic material blended with fibers, the articlehaving hidden ribs.
 43. The article according to claim 42, wherein thefibers have lengths of at least three inches long.
 44. The articleaccording to claim 42, wherein the concentration of fibers is at leastapproximately 10 percent.
 45. The article according to claim 42, whereinthe concentration of fibers is at least approximately 40 percent.
 46. Anarticle formed of an extruded composite material comprising athermoplastic material blended with fibers, the article havingstructural features including different draft depths.
 47. The articleaccording to claim 46, wherein the fibers have lengths of at leastapproximately three inches long.
 48. The article according to claim 46,wherein the concentration of fibers is at least approximately 10percent.
 49. The article according to claim 42, wherein theconcentration of fibers is at least approximately 40 percent.
 50. Anarticle formed of an extruded composite material comprising athermoplastic material blended with fibers having at least a portion ofan element encapsulated in the extruded composite material.
 51. Thearticle according to claim 50, wherein the entire element isencapsulated in the extruded composite material.
 52. The articleaccording to claim 50, wherein the fibers have lengths of at leastapproximately three inches long.
 53. The article according to claim 50,wherein the concentration of fibers is at least approximately 10percent.
 54. The article according to claim 50, wherein theconcentration of fibers is at least approximately 40 percent.
 55. Thearticle according to claim 50, wherein the element is a fastener. 56.The article according to claim 50, wherein the element is a stiffener.57. The article according to claim 50, wherein the element is anattachment.
 58. The article according to claim 50, wherein thethermoplastic material comprises one or more layers of thermoplasticcomposite material.
 59. The article of claim 58, wherein the one or morelayers of thermoplastic material have the same composition.
 60. Thearticle of claim 58, wherein the one or more layers of thermoplasticmaterial have different compositions.
 61. A method for forming athermoplastic structural component, said method comprising: receiving athermoplastic material; heating the thermoplastic material; receivingfibers having a predetermined fiber length; blending the fibers with theheated thermoplastic material to form a composite material; extrudingthe composite material; dynamically outputting the extruded compositematerial at different volumetric flow rates across a plane; positionallysynchronizing a mold to receive the extruded composite material inrelation to the different volumetric flow rates across the plane; andpressing the extruded composite material into the mold to form thethermoplastic structural component.
 62. The method according to claim61, further comprising forming the thermoplastic material fromthermoplastic resin.
 63. The method according to claim 61, wherein saidheating includes melting the thermoplastic material.
 64. The methodaccording to claim 61, further comprising selecting the fiber length ofat least one inch.
 65. The method according to claim 61, wherein saidoutputting of the different volumetric flow rates ranges betweenapproximately zero and 3000 pounds per hour.
 66. The method according toclaim 65, wherein said flow rate ranges between approximately 2500 and3000 pounds per hour.
 67. The method according to claim 61, wherein saidpositionally synchronizing includes translating the mold with respect tothe volumetric rates.
 68. The method according to claim 61, furthercomprising predetermining the different volumetric flow rates based oncavity volume of the mold across the plane.
 69. The method according toclaim 61, wherein the forming of thermoplastic structural componentincludes forming a pallet.
 70. The method according to claim 61, furthercomprising configuring an element in the mold to be encapsulated by thecomposite material.
 71. The method according to claim 61, wherein saiddynamic outputting of the extruded composite material is performed bycontrolling discrete flow control elements.
 72. The method according toclaim 61, wherein said mixing produces a composite material having atleast approximately 10 percent concentration of fiber by weight.
 73. Themethod according to claim 61, wherein said mixing produces a compositematerial having at least approximately 40 percent concentration of fiberby weight.
 74. A system for forming a thermoplastic structuralcomponent, said system comprising: means for receiving a thermoplasticmaterial; means for heating the thermoplastic material; means forreceiving fibers having a predetermined fiber length; means for mixingthe heated thermoplastic material with the fibers to form a compositematerial; means for extruding the composite material; means fordynamically outputting the extruded composite material at differentvolumetric flow rates across a plane; means for positionallysynchronizing a mold to receive the extruded composite material inrelation to the different volumetric flow rates across the plane; andmeans for pressing the extruded composite material into the mold to formthe thermoplastic structural component.
 75. The system according toclaim 74, further comprising means for forming the thermoplasticmaterial from thermoplastic resin.
 76. The system according to claim 74,wherein said means for heating includes means for melting thethermoplastic material.
 77. The system according to claim 74, whereinsaid means for positionally synchronizing includes means for translatingthe mold with respect to the volumetric rates.
 78. The system accordingto claim 74, further comprising means for predetermining the differentvolumetric flow rates based on cavity volume of the mold across theplane.
 79. The system according to claim 74, further comprising meansfor setting a non-thermoplastic element in the mold to be encapsulatedby the composite material.
 80. The system according to claim 74, whereinsaid means for mixing produces a composite material having at leastapproximately 10 percent concentration of fiber.
 81. The systemaccording to claim 74, wherein said means for mixing produces acomposite material having at least approximately 40 percentconcentration of fiber.
 82. A system for forming a thermoplasticstructural component, said system comprising: a material receiving unitoperable to receive a thermoplastic material and stiffening material; aheater unit operable to heat the thermoplastic material; an extrudercoupled to the material receiving unit and operable to extrude thecomposite material; a dynamic die having a plurality of selectablyalterable flow control elements operable to control output of thecomposite material; a mobile unit operable to support a mold and to bedynamically positioned below the dynamic die; a controller electricallycoupled to said dynamic die and mobile unit, said controller operable todynamically alter said flow control elements to output the extrudedcomposite material at different volumetric flow rates across a plane andposition said mobile unit in synchronicity with the altering of saidflow control elements to apply the extruded composite material onto themold; and a press operable to receive said mobile unit and press theextruded composite material into the mold.
 83. The system according toclaim 82, wherein said material receiving unit includes at least onefeeder.
 84. The system according to claim 82, wherein said heater unitis further operable to heat the thermoplastic material to a meltedthermoplastic state.
 85. The system according to claim 82, wherein saidextruder includes a dynamic element operable to substantially avoiddamaging the stiffening material.
 86. The system according to claim 85,wherein the stiffening material is formed of fibers having apredetermined maximum length of approximately one inch.
 87. The systemaccording to claim 85, wherein the stiffening material is formed offibers having a predetermined maximum length of approximately threeinches.
 88. The system according to claim 72, wherein the dynamicelement is a screw having a thread spacing larger than the maximumlength of the stiffening material.
 89. The system according to claim 72,wherein said mobile unit has revolving elements coupled thereto.
 90. Thesystem according to claim 89, wherein said mobile unit includes at leastone dynamic positioning element operable to engage and disengage therevolving elements.
 91. The system according to claim 90, wherein saidcontroller is operable to disengage the revolving elements while saidmobile unit is positioned in said press for the extruded compositematerial to be pressed into the mold.
 92. The system according to claim82, wherein the composite material is formed having a concentration ofapproximately 10 percent by weight of stiffening material.
 93. A methodfor forming a structural part from thermoplastic material and fiber,said method comprising: positioning an insert in a mold; depositingmolten extruded composite material on the mold; forming extrudedcomposite material about at least a portion of the insert; removingsupports, if any, used to configure the insert in the mold; compressingthe extruded composite material to form the structural part; andremoving the structural part with the insert at least partially embeddedfrom the mold.
 94. The method according to claim 93, wherein saidpositioning of the insert is performed in a lower portion of the mold.95. The method according to claim 93, wherein said depositing the moltenextruded composite material is performed dynamically across a plane. 96.The method according to claim 93, wherein said forming the extrudedcomposite material includes encapsulating the entire insert within theextruded composite material.
 97. The method according to claim 93,further comprising pressing the extruded composite material in the mold.98. A system for forming a structural part from thermoplastic materialand fiber, said system comprising: means for configuring an insert in amold; means for depositing molten extruded composite material on themold; means for forming extruded composite material about at least aportion of the insert; means for removing supports, if any, used toconfigure the insert in the mold; means for compressing the extrudedcomposite material to form the structural part; and means for removingthe structural part with the insert at least partially embedded from themold.
 99. The system according to claim 98, wherein said means forconfiguring of the insert is coupled to a lower portion of the mold.100. The system according to claim 98, wherein said means for depositingthe molten extruded composite material includes means for dynamicallyflowing the extruded composite material across a plane.
 101. The systemaccording to claim 98, wherein said means for forming the extrudedcomposite material includes means for encapsulating the entire insertwithin the extruded composite material.
 102. The system according toclaim 98, further comprising means for pressing the extruded compositematerial in the mold.